A lithium-sulfur battery cathode is sulfur, and a lithium-sulfur battery anode is elemental lithium. During electrical discharge process, the elemental lithium loses electrons to become lithium-ion, the sulfur reacts with the lithium-ion and electrons to produce lithium sulfides. A reaction equation is expressed as follows: S8+16Li++16e−1=8Li2S. A lithium-sulfur battery has advantages of low-cost, environmental friendliness, good safety, and high theoretical specific capacity.
Separator is an important component in the lithium-sulfur battery. The separator is used to separate the cathode and the anode to avoid an internal short-circuit. Conventional lithium-sulfur battery separator is polypropylene (PP), polyethylene (PE) or other non-polar films. However, polysulfides formed during an electrical discharge process have a high polarity and can easily dissolve into an electrolyte. Therefore, conventional lithium-sulfur battery separators are difficult to inhibit polysulfide diffusion. With a great loss of active sulfur, a “shuttle effect” would occur between electrodes. Thus the specific capacity and cycling stability of the lithium-sulfur battery would be limited.